Problem with the JScrollPane

[Manoj Paul]

Hello Everybody there

I am creating an application....

In my application i put a JScrollPane, in the JScrollPane is a JPanel, on the JPanel are thumbnails views of many images with the help of ImageIcons for which i used array of JLabels... Every thing is fine working untill i drag down the scrollbar... as soon as i drag down the JScrollPane's vertical or horizontal bar.. i dont know why but all the other images becomes hazy(very unclear) except those images which is shown first when i click on an image folder... i tried many options but all in vain... please help..

My Code is as follows:
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import javax.swing.JFrame;
import java.awt.Dimension;
import javax.swing.JScrollPane;
import java.awt.Rectangle;
import javax.swing.JTree;
import javax.swing.JPanel;
import javax.swing.JLabel;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.*;
import java.net.*;
import java.text.SimpleDateFormat;

import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.awt.Panel;
import java.awt.BorderLayout;
import javax.swing.JEditorPane;
import javax.swing.JTextArea;
import javax.swing.JList;

import javax.swing.SwingConstants;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JSpinner;
import java.awt.GridBagLayout;
import java.awt.event.ContainerEvent;
import javax.swing.event.AncestorListener;
import javax.swing.event.AncestorEvent;

public class SnapsGallery extends JFrame
{
public static final ImageIcon ICON_COMPUTER =new ImageIcon("computer.gif");
public static final ImageIcon ICON_DISK =new ImageIcon("disk.gif");
public static final ImageIcon ICON_FOLDER =new ImageIcon("folder.gif");
public static final ImageIcon ICON_EXPANDEDFOLDER =new ImageIcon("expandedfolder.gif");

protected DefaultTreeModel m_model;
protected JPopupMenu m_popup;
protected Action m_action;
protected TreePath m_clickedPath;

ImageIcon firstImage;
Color bgColor;
String[] holdPat=null;
BufferedImage[] images;
JLabel label[];
JCheckBox imageCheckBox[];
JLabel jLabel1 = new JLabel();


public String path="";
public String filePath="";
private Vector imageNames;
Dimension size = new Dimension(80, 60);

private JScrollPane jScrollPane1 = new JScrollPane();
private JTree jTree1;
private JScrollPane jScrollPane2 = new JScrollPane();
private JPanel jPanel1 = new JPanel();
private BorderLayout borderLayout1 = new BorderLayout();

// = new JTree();

public static void main(String a[])
{
SnapsGallery obj=new SnapsGallery();
obj.setVisible(true);
}
public SnapsGallery()
{
DefaultMutableTreeNode top = new DefaultMutableTreeNode(new IconData(ICON_COMPUTER, null, "My Computer")); // for the root of the tree

DefaultMutableTreeNode node;
File[] roots = File.listRoots(); /// for the nodes of the tree
for (int k=0; k<roots.length; k++)
{
node = new DefaultMutableTreeNode(new IconData(ICON_DISK,
null, new FileNode(roots[k])));
top.add(node);
node.add(new DefaultMutableTreeNode( new Boolean(true) ));
}

m_model = new DefaultTreeModel(top);
jTree1 = new JTree(m_model);
jTree1.putClientProperty("JTree.lineStyle", "Angled");

TreeCellRenderer renderer = new
IconCellRenderer();
jTree1.setCellRenderer(renderer);

jTree1.addTreeExpansionListener(new
DirExpansionListener());

jTree1.addTreeSelectionListener(new
DirSelectionListener());

jTree1.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
jTree1.setShowsRootHandles(true);
jTree1.setEditable(false);

m_popup = new JPopupMenu(); // to pop-up the nodes when clicked
m_action = new AbstractAction()
{
public void actionPerformed(ActionEvent e)
{
if (m_clickedPath==null)
return;
if (jTree1.isExpanded(m_clickedPath))
jTree1.collapsePath(m_clickedPath);
else
jTree1.expandPath(m_clickedPath);
}
};
m_popup.add(m_action);
m_popup.addSeparator();

Action a1 = new AbstractAction("Delete")
{
public void actionPerformed(ActionEvent e)
{
jTree1.repaint();
JOptionPane.showMessageDialog(SnapsGallery.this,
"Delete option is not implemented",
"Info", JOptionPane.INFORMATION_MESSAGE);
}
};
m_popup.add(a1);

Action a2 = new AbstractAction("Rename")
{
public void actionPerformed(ActionEvent e)
{
jTree1.repaint();
JOptionPane.showMessageDialog(SnapsGallery.this,
"Rename option is not implemented",
"Info", JOptionPane.INFORMATION_MESSAGE);
}
};
m_popup.add(a2);
jTree1.add(m_popup);
jTree1.addMouseListener(new PopupTrigger());

setVisible(true);
try
{
jbInit();
}
catch(Exception e)
{
e.printStackTrace();
}

}

private void jbInit() throws Exception
{
this.getContentPane().setLayout(null);
this.setSize(new Dimension(601, 574));

jScrollPane1.setBounds(new Rectangle(0, 0, 160, 545));
jScrollPane2.setBounds(new Rectangle(160, 0, 400, 515));
jScrollPane2.getViewport().setLayout(borderLayout1);
jScrollPane2.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
jScrollPane2.setBackground(Color.orange);
jPanel1.setLayout(null);
jPanel1.setBackground(SystemColor.activeCaptionText);
jPanel1.setPreferredSize(new Dimension(5000,5000));

jPanel1.repaint();


jScrollPane1.getViewport().add(jTree1, null);

jScrollPane2.getViewport().add(jPanel1, BorderLayout.CENTER);
this.getContentPane().add(jScrollPane2, null);
this.getContentPane().add(jScrollPane1, null);
}
DefaultMutableTreeNode getTreeNode(TreePath path)
{
return (DefaultMutableTreeNode)(path.getLastPathComponent());
}
FileNode getFileNode(DefaultMutableTreeNode node)
{
if (node == null)
return null;
Object obj = node.getUserObject();
if (obj instanceof IconData)
obj = ((IconData)obj).getObject();
if (obj instanceof FileNode)
return (FileNode)obj;
else
return null;
}
class DirSelectionListener
implements TreeSelectionListener
{
public void valueChanged(TreeSelectionEvent event)
{
repaint();
DefaultMutableTreeNode node = getTreeNode(
event.getPath());
FileNode fnode = getFileNode(node);
if (fnode != null)
{
String holdPath=fnode.getFile().getAbsolutePath();

File myDirectory = new File(fnode.getFile().getAbsolutePath());

if ( myDirectory.exists() && myDirectory.isDirectory() )
{
// List the files
String[] fileNameList = myDirectory.list();

String holdFiles="";

for(int u=0;u<fileNameList.length;u++)
{
holdFiles=holdFiles+" "+fileNameList[u];
}

showLists(holdFiles,holdPath);
}
}
}
}

public void showLists(String files,String holdPath)
{

String imageNamesString=files;
path=holdPath.replace('\\','/');
imageNames = parseList(imageNamesString);

int is=imageNames.size();
String holdFileName="";
String extent="";
int s=0;

for(int i=0;i<imageNames.size();i++)
{
holdFileName= imageNames.elementAt(i).toString();
extent=holdFileName.substring(holdFileName.lastIndexOf('.')+1,holdFileName.length());
extent=extent.toLowerCase();

if(extent.equals("jpg") || extent.equals("jpeg") || extent.equals("gif") || extent.equals("png"))
{
s++;
}
}

holdPat=new String[s];

try
{
for(int i=0,m=0;i<imageNames.size();i++)
{
holdFileName= imageNames.elementAt(i).toString();
extent=holdFileName.substring(holdFileName.lastIndexOf('.')+1,holdFileName.length());
extent=extent.toLowerCase();

if(extent.equals("jpg") || extent.equals("jpeg") || extent.equals("gif") || extent.equals("png"))
{
holdPat[m]=path+"/"+imageNames.elementAt(i);
m++;
}
}
}
catch (Exception e)
{
System.out.println("To Err Is Human: "+e);
}

try
{
images= new BufferedImage[holdPat.length];

for(int j = 0; j < holdPat.length; j++)
{
try
{
File input = new File(holdPat[j]);
images[j] = ImageIO.read(input);
}
catch(MalformedURLException mue)
{
System.out.println("url: " + mue.getMessage());
}
catch(IOException ioe)
{
System.out.println("read: " + ioe.getMessage());
}
catch(OutOfMemoryError ome)
{
System.out.println("read: " + ome.getMessage());
}
}
}
catch (Exception e)
{
System.out.println("To Err Is Human Being: "+e);
}

try
{
BufferedImage[] tnails = createThumbnails(images);
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(5,5,5,5);
gbc.weightx = 1.0;

ImageIcon ima[] = new ImageIcon[images.length];
label=new JLabel[images.length];
imageCheckBox=new JCheckBox[images.length];

int flag=0;

jPanel1.removeAll();

int a=30,b=20;

for(int j = 0,n=1; j < images.length; j++)
{
gbc.gridwidth = gbc.RELATIVE;
ima[j]=new ImageIcon(tnails[j]);
label[j]=new JLabel(ima[j]);

label[j].setBounds(a, b, 100,100 );
label[j].setBorder(new javax.swing.border.LineBorder(Color.blue, 1));

imageCheckBox[j]=new JCheckBox();
imageCheckBox[j].setBounds(a+40, b+100, 20,20 );
imageCheckBox[j].setBackground(SystemColor.activeCaptionText);

if((n%3)!=0)
{
a=a+125;
}
else
{
b=b+125;
a=30;
}
jPanel1.add(label[j],gbc);
jPanel1.add(imageCheckBox[j],null);
repaint();
}
}
catch (Exception e)
{
System.out.println("To Err Is Gentleman: "+e);
}
}

private BufferedImage[] createThumbnails(BufferedImage[] origs)
{
final int WIDTH = 100;
final int HEIGHT = 100;
BufferedImage[] images = new BufferedImage[origs.length];
try
{
AffineTransform at;

for(int j = 0; j < origs.length; j++)
{
if(origs[j]==null)
{
break;
}

images[j] = new BufferedImage(WIDTH, HEIGHT,
BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = images[j].createGraphics();
g2.setPaint(bgColor);
g2.fillRect(0, 0, WIDTH, HEIGHT);
// scale to fit

double xScale = (double)WIDTH / origs[j].getWidth();
double yScale = (double)HEIGHT / origs[j].getHeight();


double scale = Math.min(xScale, yScale);
// center thumbnail image
double x = 1;//(WIDTH - origs[j].getWidth() * scale)/2;
double y = 1;//(HEIGHT - origs[j].getHeight() * scale)/2;
at = AffineTransform.getTranslateInstance(x, y);
at.scale(scale, scale);
g2.drawRenderedImage(origs[j], at);
g2.dispose();
}
}
catch (Exception e)
{
System.out.println("To Err Is Mr.Human: "+e);
}
return images;
}

protected static Vector parseList(String theStringList)
{
Vector v=new Vector(10);
StringTokenizer tokenizer = new StringTokenizer(theStringList, " ");
while (tokenizer.hasMoreTokens())
{
String image = tokenizer.nextToken();
v.addElement(image);
}
return v;
}
class DirExpansionListener implements TreeExpansionListener
{
public void treeExpanded(TreeExpansionEvent event)
{
final DefaultMutableTreeNode node = getTreeNode(
event.getPath());
final FileNode fnode = getFileNode(node);

Thread runner = new Thread()
{
public void run()
{
if (fnode != null && fnode.expand(node))
{
Runnable runnable = new Runnable()
{
public void run()
{
m_model.reload(node);
}
};
SwingUtilities.invokeLater(runnable);
}
}
};
runner.start();
}

public void treeCollapsed(TreeExpansionEvent event) {}
}
class PopupTrigger extends MouseAdapter
{
public void mouseReleased(MouseEvent e)
{
if (e.isPopupTrigger())
{
int x = e.getX();
int y = e.getY();
TreePath path = jTree1.getPathForLocation(x, y);
if (path != null)
{
if (jTree1.isExpanded(path))
m_action.putValue(Action.NAME, "Collapse");
else
m_action.putValue(Action.NAME, "Expand");
m_popup.show(jTree1, x, y);
m_clickedPath = path;
}
}
}
}

protected static ImageIcon createImageIcon(String path)
{
File f=new File(path);
URL imgURL=null;

try
{
imgURL = f.toURL();
}
catch (MalformedURLException e)
{
}

if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}

}// end of main class




class FileNode
{
protected File m_file;

public FileNode(File file)
{
m_file = file;
}

public File getFile()
{
return m_file;
}

public String toString()
{
return m_file.getName().length() > 0 ? m_file.getName() :
m_file.getPath();
}

public boolean expand(DefaultMutableTreeNode parent)
{
DefaultMutableTreeNode flag =
(DefaultMutableTreeNode)parent.getFirstChild();
if (flag==null) // No flag
return false;
Object obj = flag.getUserObject();
if (!(obj instanceof Boolean))
return false; // Already expanded

parent.removeAllChildren(); // Remove Flag

File[] files = listFiles();
if (files == null)
return true;

Vector v = new Vector();

for (int k=0; k<files.length; k++)
{
File f = files[k];
if (!(f.isDirectory()))
continue;

FileNode newNode = new FileNode(f);

boolean isAdded = false;
for (int i=0; i<v.size(); i++)
{
FileNode nd = (FileNode)v.elementAt(i);
if (newNode.compareTo(nd) < 0)
{
v.insertElementAt(newNode, i);
isAdded = true;
break;
}
}
if (!isAdded)
v.addElement(newNode);
}

for (int i=0; i<v.size(); i++)
{
FileNode nd = (FileNode)v.elementAt(i);
IconData idata = new IconData(SnapsGallery.ICON_FOLDER,
SnapsGallery.ICON_EXPANDEDFOLDER, nd);
DefaultMutableTreeNode node = new
DefaultMutableTreeNode(idata);
parent.add(node);

if (nd.hasSubDirs())
node.add(new DefaultMutableTreeNode(
new Boolean(true) ));
}

return true;
}

public boolean hasSubDirs()
{
File[] files = listFiles();
if (files == null)
return false;
for (int k=0; k<files.length; k++)
{
if (files[k].isDirectory())
return true;
}
return false;
}

public int compareTo(FileNode toCompare)
{
return m_file.getName().compareToIgnoreCase(
toCompare.m_file.getName() );
}

protected File[] listFiles()
{
if (!m_file.isDirectory())
{
JOptionPane.showMessageDialog(null,"Error reading directory "+m_file.getAbsolutePath(),"Warning", JOptionPane.WARNING_MESSAGE);
return null;
}
try
{
return m_file.listFiles();
}
catch (Exception ex)
{
JOptionPane.showMessageDialog(null,
"Error reading directory "+m_file.getAbsolutePath(),
"Warning", JOptionPane.WARNING_MESSAGE);
return null;
}
}
}// end of FileNode class

class IconCellRenderer
extends JLabel
implements TreeCellRenderer
{
protected Color m_textSelectionColor;
protected Color m_textNonSelectionColor;
protected Color m_bkSelectionColor;
protected Color m_bkNonSelectionColor;
protected Color m_borderSelectionColor;

protected boolean m_selected;

public IconCellRenderer()
{
super();
m_textSelectionColor = UIManager.getColor(
"Tree.selectionForeground");
m_textNonSelectionColor = UIManager.getColor(
"Tree.textForeground");
m_bkSelectionColor = UIManager.getColor(
"Tree.selectionBackground");
m_bkNonSelectionColor = UIManager.getColor(
"Tree.textBackground");
m_borderSelectionColor = UIManager.getColor(
"Tree.selectionBorderColor");
setOpaque(false);
}

public Component getTreeCellRendererComponent(JTree tree,
Object value, boolean sel, boolean expanded, boolean leaf,
int row, boolean hasFocus)

{
DefaultMutableTreeNode node =
(DefaultMutableTreeNode)value;
Object obj = node.getUserObject();
setText(obj.toString());

if (obj instanceof Boolean)
setText("Retrieving data...");

if (obj instanceof IconData)
{
IconData idata = (IconData)obj;
if (expanded)
setIcon(idata.getExpandedIcon());
else
setIcon(idata.getIcon());
}
else
setIcon(null);

setFont(tree.getFont());
setForeground(sel ? m_textSelectionColor :
m_textNonSelectionColor);
setBackground(sel ? m_bkSelectionColor :
m_bkNonSelectionColor);
m_selected = sel;
return this;
}

public void paintComponent(Graphics g)
{
Color bColor = getBackground();
Icon icon = getIcon();

g.setColor(bColor);
int offset = 0;
if(icon != null && getText() != null)
offset = (icon.getIconWidth() + getIconTextGap());
g.fillRect(offset, 0, getWidth() - 1 - offset,
getHeight() - 1);

if (m_selected)
{
g.setColor(m_borderSelectionColor);
g.drawRect(offset, 0, getWidth()-1-offset, getHeight()-1);
}

super.paintComponent(g);
}
}//end of IconCellRenderer class

class IconData
{
protected Icon m_icon;
protected Icon m_expandedIcon;
protected Object m_data;

public IconData(Icon icon, Object data)
{
m_icon = icon;
m_expandedIcon = null;
m_data = data;
}

public IconData(Icon icon, Icon expandedIcon, Object data)
{
m_icon = icon;
m_expandedIcon = expandedIcon;
m_data = data;
}

public Icon getIcon()
{
return m_icon;
}

public Icon getExpandedIcon()
{
return m_expandedIcon!=null ? m_expandedIcon : m_icon;
}

public Object getObject()
{
return m_data;
}

public String toString()
{
return m_data.toString();
}
}//end of IconData
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"A Friend There To Help Me Out"

Thanks

[Joe Ess]

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